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Volume 56 (1989)
- Issue 4 Pages 453-
- Issue 3 Pages 403-
- Issue 2 Pages 215-
- Issue 1 Pages 1-
Volume 56, Issue 2
Displaying 1-15 of 15 articles from this issue
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Eiichi Otomo1989 Volume 56 Issue 2 Pages 215-221
Published: June 30, 1989
Released on J-STAGE: October 08, 2010
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Herng-huey Tsai1989 Volume 56 Issue 2 Pages 222-243
Published: June 30, 1989
Released on J-STAGE: October 08, 2010
JOURNAL FREE ACCESSThe purpose of the present study was to find the factors that affect the alignment of the upper permanent lateral incisors in early mixed dentition.
The materials, consisting of dental casts and lateral cephalograms which were taken from 30 children (15 males and 15 females) who had normal occlusion in deciduous dentition and normal permanent central incisor relationship, were divided into three groups, according to the bilateral symmetry alignment of the upper permanent lateral incisors (Group A: Normal alignment, Group B: Linguoversion, Group C: Mesiolinguotorsiversion) .
The principal component analysis was carried out to clarify the characteristics among the multi-variates, which are upper incisor shape, dental arch form, craniofacial morphology and amount of lento-craniofacial development, in Groups A, B and C.
The results obtained were as follows:
Group A shows a tendency to be harmonious in upper permanent incisor shape, dental arch form, craniofacial morphology and dento-craniofacial development.
Group B shows a tendency to have a larger labio-lingual width of the upper permanent incisors, less anterior arch length development and less forward movement of the upper permanent lateral incisor in the maxilla before eruption.
Group C shows a tendency to have a larger mesio-distal width of the upper permanent incisors, less anterior arch width development, longer distance between the upper permanent lateral incisor edge and the nasal floor and more forward and descent movement of the upper permanent lateral incisor in the maxilla before eruption.View full abstractDownload PDF (2378K) -
Hiroyuki Morisue1989 Volume 56 Issue 2 Pages 244-262
Published: June 30, 1989
Released on J-STAGE: October 08, 2010
JOURNAL FREE ACCESSTo elucidate the possible toxicity of heavy metals in a renal tubular epithelial cell line derived from a normal cynomolgus female monkey (JTC-12. P3 (F) ), the effects of HgCl2, Na2CrO4 and NiCl2 on the dome formation and the release of intrinsic enzymes from the cells were studied. The results were as follows:
1. The JTC-12. P3 (F) cells showed an evident dome formation when an inducer of differentiation (hexamethylene bisacetamide or N, N-dimethylformamide) was added to the medium.
2. Ouabain inhibited the dome formation of the JTC-12. P3 (F) cells, suggesting that the dome formation is dependent on the active transepithelial transport of Na+.
3. The addition of 40μM HgCl2, 10μM Na2CrO4 or 20μM NiCl2 inhibited the dome formation. 40μM HgCl2, 10μM Na2CrO4 or 150μM NiCl2 caused significant cell death.
4. The addition of 5μM HgCl2, 1μM Na2CrO4 or 20μM NiCl2 resulted in an increased release of lactate dehydrogenase into the medium for 6 hours. 20μM HgCl2, 1μM Na2CrO4 or 20μM NiCl2 increased the medium γ-glutamyl transpeptidase concentration for 6 hours, but 40μM HgCl2, 5μM Na2CrO4 or 100μM NiCl2 did not cause a significant increase in the medium alkaline phosphatase concentration.
The results suggest that the JTC-12. P3 (F) cells possess, at least in part, functional characteristics similar to the other kidney proximal tubular cells and that the inhibition of dome formation and enzyme release from the cells may be the early indicators that predict metal toxicity to the cells.View full abstractDownload PDF (15752K) -
Tsuyoshi Kodama1989 Volume 56 Issue 2 Pages 263-288
Published: June 30, 1989
Released on J-STAGE: October 08, 2010
JOURNAL FREE ACCESSThe biocompatibility of two different titanium alloys, Ti-6Al-4V ELI and Ti-5Al-2. 5Fe, and pure titanium were evaluated. The results were as follows
1) Titanium alloys were implanted into the dorsal subcutaneous tissues of the Hartley guinea-pig for 12 weeks, immersed in calf serum or in Ringer's solution for 8 weeks. The surface changes of the titanium alloys were observed by SEM and the chemical composition was analyzed by XMA. No evident surface changes were found.
2) Three hundred mg, 200 mg and 100 mg of the powders of the tested materials were immersed in 2ml of Eagle's MEM, incubated for 1-7 days, 8-21 days and 2270 days at 37°C.
The amount of metallic elements dissolved in the solutions was measured by ICP and AAS.
The detected corrosion rates of V and Al contained in the solution, in which Ti-6Al-4V ELI 100 mg was immersed for 1-7 days, were 194.3±17.6 and 73.0±28.1 pg/mg alloy/day, respectively. V was released more than Al.
The amount of Ti was below the detectable limit.
The solution Ti-5A1-2.5 Fe 100 mg immersed for 1-7 days contained 31.9±34.4 pg/mg alloy/day Fe and 25.7±6.3 pg/mg alloy/day Al. Only in the solution 300 mg immersed for 1-7 days was Ti detected at 1.4 pg/mg alloy/day.
3) By the bacterial mutation assay of Salmonella typhimurium TA 98, Salmonella typhimurium TA 100 and Escherichia coli WP2 uvrA-, the solutions, in which the tested materials were immersed, were not found to be mutagenic.
4) By the UDS assay, the grain counts on autoradiography with the solutions, in which the tested materials were immersed, were not greater than the negative control.
The results suggest an excellent corrosion resistance of the titanium alloys.
Mutagenicity was negative by these mutation assays, indicating that the tested alloys and pure titanium are safe for humans and animals.View full abstractDownload PDF (9524K) -
Takayuki Masuda1989 Volume 56 Issue 2 Pages 289-313
Published: June 30, 1989
Released on J-STAGE: October 08, 2010
JOURNAL FREE ACCESSThe purpose of this study was to investigate the possibility of applying the hydroxyapatite dental implant to the jawbone with atrophic structure. The lower P3, P4 and the mesial root of M1 of 6 mongrel dogs were extracted. At 4 months, the trabeculae were taken out and porous hydroxyapatite granules were filled in the vacant spongiosa. At 8 months, hydroxyapatite dental implants were placed into this area. After 1 week and after 2 months, specimens were taken out and fixed by 10% formalin alcohol. They were embedded in polyester resin and undecalcified thin sections were prepared. The sections were stained with toluidine blue and observed under light microscopy. Results: 1) A larger amount of bone compared with that of the peripheral spongiosa was observed among the granules. 2) One week after implantation, differentiation around the implant was rathers slow in the area of the granules. But in the area of the granules next to the spongiosa, differentiation was normal. 3) Two months after implantation, a new bone was observed, which filled the implantation space and united the implant to the bone among the granules. But on some implant surface, a fibrous connective tissue was seen. These results suggest that this method is able to improve the jawbone structure sufficiently to apply the hydroxyapatite dental implant.View full abstractDownload PDF (12838K) -
Katsumi Uoshima1989 Volume 56 Issue 2 Pages 314-346
Published: June 30, 1989
Released on J-STAGE: October 08, 2010
JOURNAL FREE ACCESSThe purpose of this study was to investigate the possibility of applying the hydroxyapatite dental implant to the atrophic mandible after alveolar ridge augmentation using hydroxyapatite granules. The lower P3, P4 and M1 of 3 mongrel dogs were extracted. At 30 weeks, alveolar ridge augmentation was performed with porous hydroxyapatite granules. Sixteen weeks later, hydroxyapatite dental implants were applied to the area. And 4 weeks later, the specimens were taken out and fixed by 10 % formalin alcohol. They were embedded in polyester resin and prepared into undecalcified sections. And the sections were stained with toluidine blue to observe the surrouding tissue of the dental implants histologically under light microscopy.
Results: 1) Bone formation was seen in most part of the intergranular spaces. However, in the buccal area, there were some spaces in which bone formation was entirely not observed.
2) At 4 weeks after implantation, almost all of the surface of the hydroxyapatite dental mplants was attached to the surrounding osseous tissues. But in some parts of the implant surface, especially the buccal, fibrous connective tissue was seen.
3) These results provide a basis for the technique of hydroxyapatite dental implantation with porous hydroxyapatite granules in the atrophic mandibles after alveolar ridge augmentation.View full abstractDownload PDF (17476K) -
Yuzo Fujita1989 Volume 56 Issue 2 Pages 347-360
Published: June 30, 1989
Released on J-STAGE: October 08, 2010
JOURNAL FREE ACCESSIt has been reported that dental calculus contains trace elements of mercury besides lead, cadmium and zinc. The mercury is one of the hazardous metal elements from the environmental point of view.
The purpose of this study was to clarify the mechanism of the accumulation of mercury in the dental calculus.
The results were as follows:
1. The concentration of mercury was 1.6 ppm in the dental calculus collected from the sub-jects with no amalgam fillings.
2. The most of the mercury was found in the organic fraction of the dental calculus.
3. In the culture study of Bacterionema matruchotii in vitro, with the increase of Bacterio-nema matruchotii the uptake of mercury by the bacteria increased. And the maximum uptake of mercury was seen between 7 to 14 days of the culture period.
4. After 7 days of culture, the bacterial cells were destroyed into several fractions and the quantity of the mercury in the respective fractions was assayed. About 90% of mercury was found in the cell wall.
From these results, it was suggested that the uptake of mercury by the bacteria was the cause of mercury accumulation in the dental calculus.View full abstractDownload PDF (1699K) -
Tzuu-Zenn Lin1989 Volume 56 Issue 2 Pages 361-380
Published: June 30, 1989
Released on J-STAGE: October 08, 2010
JOURNAL FREE ACCESSThe purpose of this study is to investigate the craniofacial morphology and the growth pattern in the frontal dimension of Japanese children with malocclusion.
Nine hundred twenty-one subjects composed of 343 males and 578 females without any orthodontic treatment, age ranging from 7 years to 18 years, were classified into 3 types of facial skeletal pattern according to the A-B difference in lateral cephalogram.
The direct measurement of the width and the relative ratio of the craniofacial components to the cranium were used for the parameter of the craniofacial size and shape.
The following results were obtained:
1. Independently of malocclusion, the craniofacial size of the male was significantly larger than that of the female, while the craniofacial shape of the male was almost same as that of the female.
2. In despite of the remarkable morphological difference in the lateral dimension, the characteristic morphology peculiar to a certain facial type could not be extracted in the frontal dimension.
3. In all types of malocclusion, a marked amount of growth was observed in the midf ace and mandible. However, the growth pattern of each craniofacial component in the female sample showed almost the same pattern, comparable with the different pattern of the midface and mandible in the male sample.
4. The clinical application of this study was tested in a case of Apert's syndrome.View full abstractDownload PDF (2203K) -
Teruo Kayano, Satoru Ochiai, Kazuo Kiyono, Hajime Yamamoto, Sadahiro N ...1989 Volume 56 Issue 2 Pages 381-392
Published: June 30, 1989
Released on J-STAGE: October 08, 2010
JOURNAL FREE ACCESSThe ablation effects of the Erbium: YAG laser (wave length: 2.94μm) on the human extracted teeth were examined histopathologically.
The enamel surface of the human extracted tooth was irradiated by the laser at 500 mJ, 1 pps or 3 pps; 3, 15, 30, 50 and 100 shots. After observation under a dissecting microscope, the teeth were placed in a demineralizing solution of 0.1 M lactate buffer with 6% hydroxyethyl cellulose (pH 4.5) in order to evaluate the acid resistance of the enamel adjacent to the ablated area. After 4 days, the degree of demineralization of the surrounding enamel was assessed by contact microradiography.
The result showed that every irradiated tooth had a clear-cut defect, and almost all the teeth had acquired acid resistance at the enamel surrounding the ablated portion.
The other experiment was carried out to estimate the effects of the Er: YAG laser through a contact probe. The enamel, dentin and cementum of the extracted teeth were irradiated at 39 mJ or 74 mJ, 10 pps; 10 shots. The teeth were observed under a dissecting microscope.
The result clearly indicated that the Er: YAG laser guided by the contact probe could also produce a defect in the dental hard tissue.
The above-mentioned findings suggested that the Er: YAG laser could pave the way for the cavity preparation with acid-resistant cavity margin.View full abstractDownload PDF (10748K) -
[in Japanese], [in Japanese]1989 Volume 56 Issue 2 Pages 393
Published: June 30, 1989
Released on J-STAGE: October 08, 2010
JOURNAL FREE ACCESSDownload PDF (146K) -
[in Japanese]1989 Volume 56 Issue 2 Pages 394
Published: June 30, 1989
Released on J-STAGE: October 08, 2010
JOURNAL FREE ACCESSDownload PDF (133K) -
[in Japanese]1989 Volume 56 Issue 2 Pages 395
Published: June 30, 1989
Released on J-STAGE: October 08, 2010
JOURNAL FREE ACCESSDownload PDF (153K) -
[in Japanese], [in Japanese], [in Japanese], [in Japanese]1989 Volume 56 Issue 2 Pages 396
Published: June 30, 1989
Released on J-STAGE: October 08, 2010
JOURNAL FREE ACCESSDownload PDF (149K) -
[in Japanese]1989 Volume 56 Issue 2 Pages 397
Published: June 30, 1989
Released on J-STAGE: October 08, 2010
JOURNAL FREE ACCESSDownload PDF (2255K) -
[in Japanese]1989 Volume 56 Issue 2 Pages 398
Published: June 30, 1989
Released on J-STAGE: October 08, 2010
JOURNAL FREE ACCESSDownload PDF (157K)
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